A high-beam assistant is able to detect nonhost vehicles and to switch automatically from high beam to low beam, if another vehicle is being dazzled. It may happen that the high-beam assistant switches erroneously to low beam, although no other vehicles are to be seen. Such a misdetection may come about if the reflections of the host vehicle's high beam are misinterpreted as a nonhost vehicle. One distinction of reflections and light sources is carried out, for example, in monocamera systems with the aid of the course of motion, of the position in the image or the light intensity. This may, however, frequently lead to a misdetection, since, based on the motion of the ego vehicle, or host vehicle (i.e., the vehicle in which the evaluation of the reflections takes place), the trajectory of reflection objects in the image very much corresponds to those of another vehicle at a great distance. The like applies also for the position in the image and the light intensity in the image.
German Application No. DE 10 2009 042 476 A1 describes a method for determining conditions in the surroundings of a motor vehicle using a stereo camera.